diff --git a/dwtt b/dwtt
index 9ff0614..1be6372 100755
--- a/dwtt
+++ b/dwtt
@@ -39,9 +39,13 @@ def main(argv):
 
     while True:
         cmdline = doCmdWindow()
-        cmd = Command(cmdline)
-        if not processCommand(cmd, ds):
+        if cmdline.strip() == '':
             break
+        cmd = Command(cmdline)
+        res = processCommand(cmd, ds)
+        if type(res).__name__ == 'bool':
+            if not res:
+                break
 
 def doCmdWindow():
     c = CmdWindow()